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*
* Copyright (C) 2007 - 2014 Xilinx, Inc.  All rights reserved.
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* of this software and associated documentation files (the "Software"), to deal
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*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
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* Use of the Software is limited solely to applications:
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******************************************************************************/

#include <stdlib.h>

#include "public_lib.h"
#include "xpqueue.h"

pq_queue_t pq_queue[NUM_QUEUES];
static char queue_used_flag = 0;

pq_queue_t *
pq_create_queue()
{
    pq_queue_t *q = NULL;

    for(int i=0;i<8;i++)
    {
        if(0 == GET_BIT(queue_used_flag, i))
        {
            q = &pq_queue[i];
            SET_BIT(queue_used_flag, i);
            break;
        }
    }

    if(q)
    {
        q->head = q->tail = q->len = 0;
    }

    return q;
}

void pq_delete_queue(pq_queue_t *q)
{
    for(int i=0;i<8;i++)
    {
        if((q == &pq_queue[i]) && (GET_BIT(queue_used_flag, i)))
        {
            q->head = q->tail = q->len = 0;
            CLR_BIT(queue_used_flag, i);
        }
    }
}

int pq_enqueue(pq_queue_t *q, int data)
{
    if(q==NULL){return -1;}

    if (q->len == PQ_QUEUE_SIZE){return 0;}

    q->data[q->head] = data;    

    q->head = (q->head + 1)%PQ_QUEUE_SIZE;
    q->len++;

    return 1;
}

int pq_dequeue(pq_queue_t *q, int *data)
{
    if(q==NULL){return -1;}
    if (q->len == 0) return 0;

    if(data)    {*data = q->data[q->tail];}    

    q->tail = (q->tail + 1)%PQ_QUEUE_SIZE;
    q->len--;

    return 1;
}

